Conventionally, hot melt adhesive was applied using hot melt adhesive applicators (glue guns). These glue guns were designed to be connected to a wall socket by an electrical cord and plug for continuously applying electrical power to the glue gun, thereby melting the adhesive In the glue gun. This meant that the range over which the glue gun could physically operate was determined by the length of the electrical cord coupling the glue gun to the wall socket. Moreover, the cord at times presented a physical obstacle for the user to maneuver around when using the glue gun.
To solve these problems, a cordless glue gun was designed. A cordless glue gun is a glue gun that can be detached from its source of electricity so that it can operate without an electrical cord. In designing a cordless glue gun, significant attention needs to be paid to the support structure for the gun. The support structure must conveniently support the glue gun and enable the glue gun to be electrically energized (heated) while It is on the support structure. Moreover, the support structure and the glue gun need to be designed to enable convenient release of the glue gun from the support structure and from the source of electricity when it is desired to use the glue gun. Toward these purposes, the support structure includes a socket for transmitting electrical energy to the glue gun and a release mechanism enabling the glue gun to be disconnected from the socket when it is released from the support structure.
Despite the improvements that a cordless glue gun offers over a conventional glue gun, a cordless glue gun still has drawbacks. Although the cordless glue gun does not require continuous electrical power, It must be initially electrically heated while on the support structure and may require intermittent electrical heating to maintain the hot melt adhesive in a state of low viscosity. Additionally, both the conventional glue gun and the cordless glue gun require hot melt adhesive sticks or other forms of bulk adhesive to be inserted into the glue gun. This requires the purchase of the hot melt adhesive separate from the purchase of the glue gun itself and the handling of the hot melt adhesive before each use of the glue gun. Moreover, both the conventional glue gun and the cordless glue gun are bulky, relatively expensive to purchase, need a relatively long preheating time before glue can be dispensed, and a relatively long cool down period before being stored away.
A marked improvement and innovation in the dispensing of heat sensitive materials, specifically hot melt adhesives, was made by Nottingham et al. in the aforementioned U.S. patent (U.S. Pat. No. 5,188,256), the contents of which are incorporated herein by reference, of which the present application is a continuation-in-part. Specifically, Nottingham et al. disclose a dispenser for heat sensitive materials comprising a first material which changes from a solid state or a state of high viscosity to a state of low viscosity when heated above a predetermined temperature, a second material which is adapted to be heated above a predetermined temperature when subjected to microwave energy for at least a predetermined time, a container enclosing the first and second materials, and an outlet through which the first material can be dispensed from the container when in the state of low viscosity. In the specific embodiment described therein, a hot melt adhesive is encased within a container, the inner surface of which has been coated with a microwave susceptor material .